<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <div id="app">Hello world</div>
  <script>
    window.addEventListener('DOMContentLoaded', function () {
      console.log('DOMContentLoaded')
    })
  </script>
  <script type="module" src="./modules/index.js"></script>
</body>
</html>